Wind turbines 'may actually do more harm than good'

Dubbed 'the ultimate green fashion statement', are selling in their thousands amid claims they can cut household electricity bills by 30 per cent.

But now environmental campaigners say the windmills are not quite what they claim to be - and may actually do more harm than good.

As well as being noisy and unsightly, they barely produce enough electricity to power a hairdryer in many houses.

They also do nothing to tackle greenhouses gases, while there are far better ways to cut down on energy bills.

Although there are currently just 650 home wind turbines installed that number is set to grow massively as the makers of the most popular wind turbine, Windsave, have had orders of more than 15,000 ahead of Christmas for their WS1000 unit which sells for just under £1,500 at B&Q.

Fans of wind turbines include David Cameron, who plans to install one in his west London home, Jamie Oliver, and the new science minister Malcolm Wicks.

But Friends of the Earth expert Nick Rau said there are other more practical - if less fashionable - ways of saving energy.

'A wind turbine on the roof is a glamourous statement - people want to be seen to be doing something.

'But loft or cavity wall insulation may be more effective - and will probably pay for itself a lot quicker.'

Cavity wall insulation costs around £300-£500 and can save around £150 a year in fuel bils. Wind turbines could only make a similar saving if perched on house on top of a hill in the countryside.

But turbines in towns suffer from a lack of wind - as tall buildings block the air supply. The average windspeed in Britain is 5.6 metres per second - roughly enough to generate around half a kilowatt of electricity, or enough to power a hairdryer.

This would work out at a maximum saving of £100 a year - so it would take around 15 years to pay for itself.

Wind turbines do not figure in the top ten ways to save energy in Britain.The government's Energy Saving Trust recommends 10 more energy efficient measures, such as lagging the hotwater tank, cavity wall installation, using low-energy light bulbs, drawing the curtains at night, and turning the thermostat down by one degree.

The turbines must be professionally installed and can, in some instances, result in the whole house vibrating.

Jane Vaus, of the Micropower Council, an industry body promoting small scale energy generation said: 'There is a bit of novelty value at the moment. You wouldn't say to friends ''come look at my cavity wall insulation''. But a wind turbine is much more interesting.'

Alternative energy expert Nick Martins, warns that the turbine can cause instability on some buildings.

He said 'This is not the same thing as fitting a satellite dish on the side of a house. I would guess that the lateral thrust exerted by these turbines on a Victorian chimney stack in a high wind would be more than sufficient to topple it.'

The noise generated by a Windsave turbine is 40 decibels - 'the sound of two people walking in front of your house talking' according to Paul Johnson, buying manager for B&Q.

The DIY giant said that structural surveys will reveal whether the building is strong enough to take the structure - and would never fit it to a chimney.

'We have had to turn a few people down as their roofs are not strong enough,' he said. The turbines have to have planning permission as well.

B&Q said the turbines are on sale in 107 out of their 320 shops. She said: 'Since going on sale, the biggest selling product line in value out of 43,000 items is our £1,500 wind turbine.'

Scotland has had the biggest sales so far, followed by the West Midlands, London and the Home Counties.